Field
Apparatuses and methods of the disclosure relate to a display apparatus with a local dimming backlight and a control method thereof, and for example to a display apparatus, a light emitting diode (LED) driving circuit and a method of controlling the same, in which a plurality of local dimming backlight blocks is driven and controlled by one controller, thereby decreasing complication of the circuit and reducing material costs.
Description of Related Art
A display apparatus including a display panel displays an image based on a broadcast signal or an image signal/image data of various formats, and is achieved by a television (TV), a monitor, etc. The display panel may be variously achieved by a liquid crystal display panel, a plasma display panel, etc. in accordance with its characteristics, and used for various display apparatuses. Recently, a liquid crystal display (LCD) has been employed as a display device for a display panel in various fields from a screen for a smart phone to a screen for a large LCD TV. Since the LCD is a non light emitting element, the LCD needs a backlight for illumination in order to display an image.
The backlight for the LCD is required to make generally uniform brightness, be thin and lightweight in the case of a portable LCD, and have low power consumption. The backlight currently used for the LCD includes a light emitting diode (LED), an electro luminescent device (EL), a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL), a flat lamp (FL), etc.
Among them, the LED has been in the limelight as the backlight for the LCD since it consumes less power than the CCFL, solves a problem of the EL having a short lifespan, and reduces environmental pollution due to mercury that is a main material for the fluorescent lamp and has recently become an issue.
Further, to improve the quality of an image displayed on the LCD, local dimming technology, for example, dividing backlight into a plurality of blocks for individual dimming control, has been widespread. Thus, the backlight is divided into a plurality of areas, and the brightness is decreased in the areas corresponding to a dark color of an image and increased in the areas corresponding to a bright color of the image in association with an image signal, thereby improving not only contrast but also distinction. In addition, the plurality of areas are driven in sequence through the local dimming, thereby decreasing a motion blur.
For local dimming, a light guide plate that uniformly guides incident light to the display panel, the backlight that is evenly divided into blocks and emits light, and a control driver that is provided in each block and drives the backlight, are required. As the number of divided or sectioned blocks increases, the control drivers respectively provided in the blocks result in a complicated circuit, increase material costs, and increase production costs of the display apparatus.